Shell腳本中常用的控制結構

if ... then語句

if [ test_command ]

then

commands

fi

if ... then ... else語句

if [ test_command ]

then

commands

else

commands

fi

if ... then ... elif ... (else)語句

if [ test_command ] then

commands

elif [ test_command ]

then

commands

...

...

else  (optional)

commands

fi

for ... in語句

for 變量 in 變量列表 do

commands

done

while語句

while 條件為真 do

commands

done

until語句

until 條件為真 do

commands

done

case語句

case $variable in match_1)

commands_to_execute_for_1 ;;

match_2)

commands_to_execute_for_2 ;;

match_3)

commands_to_execute_for_3 ;;

...

...

*)  (可選 - any other value)

commands_to_execute_for_no_match

;;

esac